[llvm] [clang] [SystemZ][z/OS] This change adds support for the PPA2 section in zOS (PR #68926)

[Ulrich Weigand via cfe-commits]

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@@ -976,6 +976,40 @@ void CodeGenModule::Release() {
       Context.getTypeSizeInChars(Context.getWideCharType()).getQuantity();
   getModule().addModuleFlag(llvm::Module::Error, "wchar_size", WCharWidth);
 
+  if (getTriple().isOSzOS()) {
+    getModule().addModuleFlag(llvm::Module::Warning,
+                              "zos_product_major_version",
+                              uint32_t(CLANG_VERSION_MAJOR));
+    getModule().addModuleFlag(llvm::Module::Warning,
+                              "zos_product_minor_version",
+                              uint32_t(CLANG_VERSION_MINOR));
+    getModule().addModuleFlag(llvm::Module::Warning, "zos_product_patchlevel",
+                              uint32_t(CLANG_VERSION_PATCHLEVEL));
+    std::string ProductId;
+#ifdef CLANG_VENDOR
+    ProductId = #CLANG_VENDOR;
+#else
+    ProductId = "clang";
+#endif
+    getModule().addModuleFlag(llvm::Module::Error, "zos_product_id",
+                              llvm::MDString::get(VMContext, ProductId));
+
+    // Record the language because we need it for the PPA2.
+    StringRef lang_str = languageToString(
+        LangStandard::getLangStandardForKind(LangOpts.LangStd).Language);
+    getModule().addModuleFlag(llvm::Module::Error, "zos_cu_language",
+                              llvm::MDString::get(VMContext, lang_str));
+
+    time_t TT = PreprocessorOpts.SourceDateEpoch
+                    ? *PreprocessorOpts.SourceDateEpoch
+                    : std::time(nullptr);
+    getModule().addModuleFlag(llvm::Module::Max, "zos_translation_time",
+                              static_cast<uint64_t>(TT));
+
+    getModule().addModuleFlag(llvm::Module::Error, "zos_le_char_mode",
+                              llvm::MDString::get(VMContext, "ascii"));
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uweigand wrote:

Is "ascii" the correct default here?   In either case, please add a comment stating multiple modes will be supported in the future, so we understand why this code is here.

https://github.com/llvm/llvm-project/pull/68926